Develop Reference

Button with progress bar android

I am trying to create a custom button with progress bar inside of it in Android.
The button should have 2 states:
Normal and Loading.
In Normal state it should show a text while in Loading state it should show a centerred circular progress indicator instead of the text!
When the button state returns to "Normal" state it should show the text again.
To achieve this, I've thought about create a custom view which build from a RelativeLayout
and inside of it there is a TextView and a Circular progress indicator and change their visibility in code according to the state.
This idea and logic works pretty good.
Please refer to images of my buttons with the progress indicators:
However, the problem comes when I want to apply a selector to this view,
I've created a style and a selector for each button but it just not setting the right background to the view when its disabled.
A RelativeLayout doesn't has an enabled attribute available in its xml so I had to add a styleable attr and change its state in code with isEnabled = false or something like that.
This makes it disabled in did, but the background stays as it is enabled (The selector not working).
This is my "Button" source code:
class ProgressButton #JvmOverloads constructor(
context: Context,
attrs: AttributeSet? = null,
defStyleAttr: Int = 0
) : RelativeLayout(context, attrs, defStyleAttr) {
private val progressBar: LottieAnimationView
private val buttonTextView: TextView
init {
val root = LayoutInflater.from(context).inflate(R.layout.progress_button, this, true)
buttonTextView = root.findViewById(R.id.button_text)
progressBar = root.findViewById(R.id.progress_indicator)
loadAttr(attrs, defStyleAttr)
}
private fun loadAttr(attrs: AttributeSet?, defStyleAttr: Int) {
val arr = context.obtainStyledAttributes(
attrs,
R.styleable.ProgressButton,
defStyleAttr,
0
)
val buttonText = arr.getString(R.styleable.ProgressButton_text)
val loading = arr.getBoolean(R.styleable.ProgressButton_loading, false)
val enabled = arr.getBoolean(R.styleable.ProgressButton_enabled, true)
isEnabled = enabled
arr.recycle()
buttonTextView.text = buttonText
setLoading(loading)
}
fun setLoading(loading: Boolean){
if(loading){
buttonTextView.visibility = View.GONE
progressBar.visibility = View.VISIBLE
} else {
buttonTextView.visibility = View.VISIBLE
progressBar.visibility = View.GONE
}
}
}
This its layout:
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="50dp">
<TextView
android:id="#+id/button_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:textAppearance="?android:attr/textAppearanceButton"
android:text="OK" />
<com.airbnb.lottie.LottieAnimationView
android:id="#+id/progress_indicator"
android:layout_width="#dimen/progressbar_width"
android:layout_height="#dimen/progressbar_width"
android:layout_centerInParent="true"
android:visibility="gone"
app:lottie_autoPlay="true"
app:lottie_loop="true"
app:lottie_rawRes="#raw/lottile_button_loader" />
</RelativeLayout>
This a the background with selector for it:
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<corners android:radius="#dimen/components_corner_radius" />
<solid android:color="#color/button_black_bg_selector" />
</shape>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:color="#color/black" android:state_enabled="true" />
<item android:color="#color/buttons_black_pressed" android:state_pressed="true" />
<item android:color="#color/buttons_black_disabled" android:state_enabled="false" />
<item android:color="#color/black" />
This is the styling and theme:
<style name="Theme.Widget.ProgressButton" parent="">
<item name="android:textAppearanceButton">#style/TextAppearance.Body.White</item>
</style>
<style name="Widget.ProgressButton.Black" parent="#style/Theme.Widget.ProgressButton">
<item name="android:colorControlHighlight">#color/buttons_black_pressed</item>
<item name="android:background">#drawable/progress_button_black</item>
</style>
And finally, this how i use it in a fragment layout xml:
<com.example.widgets.ProgressButton
android:id="#+id/button_black_loading"
android:theme="#style/Widget.ProgressButton.Black". //This is where it gets its style and theme
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_marginHorizontal="24dp"
android:layout_marginTop="16dp"
app:loading="true"/>
Any help will be appreciated.

Finally I've came to a pattern that seems to work with a single style line in the custom view usage xml (e.g. Fragment or Activity layout).
For each button I've defined similar styling blocks that looks like this:
<style name="Theme.Widget.Button.Black" parent="">
<item name="android:textAppearanceButton">#style/TextAppearance.BlackButton</item> //This will set the theme for the button internal TextView
<item name="android:colorControlHighlight">#color/buttons_black_pressed</item> //This will set the highlight color for ripple effect
</style>
<style name="Widget.Button.Black" parent="">
**<item name="android:theme">#style/Theme.Widget.Button.Black</item>** //Note this theme attribute which takes that above styling and applying it as a theme!!
<item name="android:background">#drawable/button_black</item> //A shape with selector drawable
</style>
The background drawable:
<ripple xmlns:android="http://schemas.android.com/apk/res/android"
android:color="?android:attr/colorControlHighlight"> //This comes from the theme for the ripple effect
<item android:drawable="#drawable/button_black_shape"/> //The selector
</ripple>
The background shape drawable:
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<corners android:radius="#dimen/components_corner_radius" />
<solid android:color="#color/button_black_bg_selector" />
</shape>
The selector:
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:color="#color/black" android:state_enabled="true" />
<item android:color="#color/buttons_black_pressed" android:state_pressed="true" />
<item android:color="#color/buttons_black_disabled" android:state_enabled="false" />
<item android:color="#color/black" />
</selector>
And finally using the button in fragment XML like this:
<com.sample.widgets.ProgressButton
android:id="#+id/button_black_enabled"
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_marginHorizontal="24dp"
android:layout_marginTop="16dp"
app:enabled="true"
app:text="OK"
style="#style/Widget.Button.Black"/> //The style brings a theme also!

After adding the selector you need to change the state of ProgressButtonI am adding essential code below which should work.
Selector should be like :-
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="#color/black" android:state_enabled="true" />
<item android:drawable="#color/buttons_black_pressed" android:state_pressed="true" />
<item android:drawable="#color/buttons_black_disabled" android:state_enabled="false" />
and ProgressButton.kt
class ProgressButton #JvmOverloads constructor(
context: Context,
attrs: AttributeSet? = null,
defStyleAttr: Int = 0
) : RelativeLayout(context, attrs, defStyleAttr) {
private val progressBar: LottieAnimationView
private val buttonTextView: TextView
init {
val root = LayoutInflater.from(context).inflate(R.layout.progress_button, this, true)
buttonTextView = root.findViewById(R.id.button_text)
progressBar = root.findViewById(R.id.progress_indicator)
loadAttr(attrs, defStyleAttr)
}
private fun loadAttr(attrs: AttributeSet?, defStyleAttr: Int) {
// this line can be removed if you are setting selector in xml
setBackgroundResource(R.drawable.button_selector)
setLoading(true)
}
fun setLoading(loading: Boolean) {
if (loading) {
buttonTextView.visibility = View.GONE
progressBar.visibility = View.VISIBLE
} else {
buttonTextView.visibility = View.VISIBLE
progressBar.visibility = View.GONE
}
isEnabled = !loading
}
}

Xamarin.Forms MasterDetail page NavBar customization

I'm in need of a large dose of help for an issue with the MasterDetail page in Xamarin.Forms.
What I'm trying to do is, very simply, to customize the NavigationBar's background to use a gradient. My setup is a Xamarin.Forms app with Prism, where I first login the user and then navigate to a MasterDetail page like so:
await NavigationService.NavigateAsync("MyMasterDetailPage/NavigationPage/MyDetailPage")
The problem I am running into is that no matter what I do I can't change the color of the NavigationBar.
I've tried several different variants of CustomRenderers (for Android currently), as well as just adding a custom TitleView to the Detail page in the PCL project. I've also tried changing the styles.xml file, changing the ToolBar.axml to use the drawable I've made, but I've still got no luck so far.
Any help would be greatly appreciated as I've been struggling for a few days now with this issue.
Below is a screenshot of what's going on:
Toolbar.axml:
<android.support.v7.widget.Toolbar
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
android:popupTheme="#style/ThemeOverlay.AppCompat.Light"
android:background="#drawable/gradient_background_drawable"
/>
styles.xml:
<?xml version="1.0" encoding="utf-8" ?>
<resources>
<style name="MainTheme" parent="MainTheme.Base">
</style>
<!-- Base theme applied no matter what API -->
<style name="MainTheme.Base" parent="Theme.AppCompat.Light.DarkActionBar">
<!--If you are using revision 22.1 please use just windowNoTitle. Without android:-->
<item name="windowNoTitle">true</item>
<!--We will be using the toolbar so no need to show ActionBar-->
<item name="windowActionBar">false</item>
<!-- Set theme colors from http://www.google.com/design/spec/style/color.html#color-color-palette -->
<!-- colorPrimary is used for the default action bar background -->
<item name="colorPrimary">#89D362</item>
<!-- colorPrimaryDark is used for the status bar -->
<item name="colorPrimaryDark">#89D362</item>
<!-- colorAccent is used as the default value for colorControlActivated
which is used to tint widgets -->
<item name="colorAccent">#FF4081</item>
<!-- You can also set colorControlNormal, colorControlActivated
colorControlHighlight and colorSwitchThumbNormal. -->
<!--<item name="windowActionModeOverlay">true</item>-->
<item name="android:datePickerDialogTheme">#style/AppCompatDialogStyle</item>
<item name="drawerArrowStyle">#style/DrawerArrowStyle</item>
</style>
<style name="AppCompatDialogStyle" parent="Theme.AppCompat.Light.Dialog">
<item name="colorAccent">#FF4081</item>
</style>
<style name="DrawerArrowStyle" parent="#style/Widget.AppCompat.DrawerArrowToggle">
<item name="spinBars">true</item>
<item name="color">#89D362</item>
</style>
</resources>
gradient_background_drawable:
<?xml version="1.0" encoding="utf-8" ?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<gradient android:type="linear"
android:angle="270"
android:startColor="#000E0E"
android:endColor="#3D3939">
</gradient>
</shape>
MasterDetailPageRenderer:
protected override void OnLayout(bool changed, int l, int t, int r, int b)
{
base.OnLayout(changed, l, t, r, b);
var toolbar = FindViewById<Android.Support.V7.Widget.Toolbar>(Resource.Id.toolbar);
if (toolbar != null)
{
for (int i = 0; i < toolbar.ChildCount; i++)
{
var child = toolbar.GetChildAt(i);
child.Background = Context.GetDrawable(Resource.Drawable.gradient_background_drawable);
}
toolbar.Background = Context.GetDrawable(Resource.Drawable.gradient_background_drawable);
}
}
NavigationPageRenderer:
protected override void OnElementChanged(ElementChangedEventArgs<NavigationPage> e)
{
base.OnElementChanged(e);
if (e.OldElement != null || Element == null)
{
return;
}
var actionBar = ((FormsAppCompatActivity)Context).SupportActionBar;
actionBar.SetBackgroundDrawable(Context.GetDrawable(Resource.Drawable.gradient_background_drawable));
}
protected override void OnLayout(bool changed, int l, int t, int r, int b)
{
base.OnLayout(changed, l, t, r, b);
var toolbar = FindViewById<Android.Support.V7.Widget.Toolbar>(Resource.Id.toolbar);
if (toolbar != null)
{
//for (int i = 0; i < toolbar.ChildCount; i++)
//{
// var child = toolbar.GetChildAt(i);
// child.Background = Context.GetDrawable(Resource.Drawable.gradient_background_drawable);
//}
toolbar.Background = Context.GetDrawable(Resource.Drawable.gradient_background_drawable);
}
}
public override void OnViewAdded(Android.Views.View child)
{
base.OnViewAdded(child);
if (child.GetType() == typeof(Android.Support.V7.Widget.Toolbar))
{
_toolbar = (Android.Support.V7.Widget.Toolbar)child;
_toolbar.Background = Context.GetDrawable(Resource.Drawable.gradient_background_drawable);
}
}

I achieved the function by creating a new app with template Master-Detail Page.
The method is to set the background of Toolbar.axml just as you mentioned.
<android.support.v7.widget.Toolbar
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
android:popupTheme="#style/ThemeOverlay.AppCompat.Light"
android:background="#drawable/gradient_background_drawable"
/>
To make the effect more obvious,I change the gradient color. You can change back to your own gradient color.
file gradient_background_drawable.xml
<?xml version="1.0" encoding="utf-8" ?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<gradient android:type="linear"
android:angle="270"
android:startColor="#008B00"
android:endColor="#9AFF9A">
</gradient>
</shape>
Besides,remember to remove the Property relatived with Background about toolbar in file App.xaml .
file App.xaml
<?xml version="1.0" encoding="utf-8" ?>
<Application xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="FormApp202011.App">
<Application.Resources>
<ResourceDictionary>
<!--Global Styles -->
<Color x:Key="NavigationPrimary">#2196F3</Color>
<Style TargetType="NavigationPage">
<Setter Property="BarTextColor" Value="Red" />
</Style>
</ResourceDictionary>
</Application.Resources>
</Application>
The result:

DialogFragment does not occupy bezel less screen

I am trying to display a dialog fragment in a bezeless phone which has a notch.
Here is the screenshot.
As you can see the dialog fragment does not occupies the whole screen and show an ugly grey color at the top.
Here is what i have tried
I am setting the style in DialogFragment
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setStyle(DialogFragment.STYLE_NORMAL, R.style.FullScreenDialogStyle)
}
<style name="FullScreenDialogStyle" parent="Theme.AppCompat.Dialog">
<item name="android:windowNoTitle">true</item>
<item name="android:windowFullscreen">true</item>
<item name="android:windowActionBar">false</item>
<item name="android:windowContentOverlay">#null</item>
<item name="android:windowIsFloating">true</item>
<item name="android:windowLayoutInDisplayCutoutMode">shortEdges</item>
</style>
I am using the same technique for Activity Screen and it works as it occupies the whole bezelless screen but this does not work for dialog fragment

You have two options here. First, let's look at the components that are common to both options;
DialogFragment's onStart method:
override fun onStart() {
super.onStart()
val dialog: Dialog? = dialog
if (dialog != null) {
val width = ViewGroup.LayoutParams.MATCH_PARENT
val height = ViewGroup.LayoutParams.MATCH_PARENT
dialog.window?.setLayout(width, height)
dialog.window?.decorView?.systemUiVisibility =
View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY or
View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION or
View.SYSTEM_UI_FLAG_FULLSCREEN
}
}
DialogFragment's onCreate method:
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setStyle(DialogFragment.STYLE_NORMAL, R.style.FullScreenDialogStyle)
}
Dialog xml:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#c92145">
<Button android:layout_width="match_parent"
android:layout_height="50dp"
android:text="Lorem ipsum dolor sit amet"/>
</LinearLayout>
FullScreenDialogStyle:
<style name="FullScreenDialogStyle" parent="Theme.AppCompat.Light.NoActionBar">
<item name="android:windowLayoutInDisplayCutoutMode">shortEdges</item>
</style>
Options:
Left (Option #1)
Add this line to FullScreenDialogStyle
<item name="android:fitsSystemWindows">true</item>
Right (Option #2)
Add this line to FullScreenDialogStyle
<item name="android:fitsSystemWindows">false</item>

In your code, you should include android "windowMinWidthMajor" and "windowMinWidthMinor" properties and set dialog.getWindow() layouts to MATCH_PARENT and make the layout in LinearLayout.
<style name="Theme_Dialog_tab" parent="Theme.AppCompat.Dialog">
<item name="android:windowMinWidthMajor">100%</item>
<item name="android:windowMinWidthMinor">100%</item>
<item name="android:windowFullscreen">true</item>
<item name="android:windowIsFloating">true</item>
<item name="android:windowBackground">#null</item>
</style>
In Java file:
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity(),R.style.Theme_Dialog);
dialog.getWindow().setLayout(ViewGroup.LayoutParams.MATCH_PARENT,ViewGroup.LayoutParams.MATCH_PARENT);
I hope it will help you....!

I found another simple solution, just try to put this code on onCreate() method :
Dialog yourDialog;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
yourDialog.getWindow().setFlags(WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS, WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS );
yourDialog.getWindow().getAttributes().layoutInDisplayCutoutMode = WindowManager.LayoutParams.LAYOUT_IN_DISPLAY_CUTOUT_MODE_SHORT_EDGES;
}

BottomSheetDialog with transparent background

I would like to display a bottom sheet dialog less wide than the screen width.
For instance, the Share option from Google Play Music on a Nexus 9.
Do you know how to achieve this ?
For now I just succed to reduce the width of the sheet content but the background is still at the screen width and display a white background.
Some code:
build.gradle
compile 'com.android.support:design:23.3.0'
MainActivity
#Override
protected void onCreate(Bundle savedInstanceState) {
...
mBottomSheetDialog = new BottomSheetDialog(this);
mBottomSheetDialog.setContentView(R.layout.sheet_test);
mBottomSheetDialog.setOnDismissListener(new DialogInterface.OnDismissListener() {
#Override
public void onDismiss(DialogInterface dialog) {
mBottomSheetDialog = null;
}
});
mBottomSheetDialog.show();
}
sheet_test
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="100dp"
android:layout_height="match_parent"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
style="#style/TextAppearance.AppCompat.Body1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="16dp"
android:text="Some Text"
android:textColor="#color/colorPrimary" />
<View
android:layout_width="match_parent"
android:layout_height="1dp"
android:background="#ddd" />
<TextView
style="#style/TextAppearance.AppCompat.Body1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="16dp"
android:text="Some Text" />
<View
android:layout_width="match_parent"
android:layout_height="1dp"
android:background="#ddd" />
</LinearLayout>
</android.support.v4.widget.NestedScrollView>

This worked for me when using BottomSheetDialogFragment:
public class CustomDialogFragment extends BottomSheetDialogFragment {
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setStyle(BottomSheetDialogFragment.STYLE_NORMAL, R.style.CustomBottomSheetDialogTheme);
}
...
}
Also add this to your styles.xml
<style name="CustomBottomSheetDialogTheme" parent="Theme.Design.Light.BottomSheetDialog">
<item name="bottomSheetStyle">#style/CustomBottomSheetStyle</item>
</style>
<style name="CustomBottomSheetStyle" parent="Widget.Design.BottomSheet.Modal">
<item name="android:background">#android:color/transparent</item>
</style>
Option 2:
override fun getTheme() = R.style.CustomBottomSheetDialogTheme

BottomSheetDialog bottomSheetDialog =new BottomSheetDialog(this,R.style.SheetDialog);
<style name="SheetDialog" parent="Theme.Design.Light.BottomSheetDialog">
<!--<item name="android:windowCloseOnTouchOutside">false</item>-->
<item name="android:windowIsTranslucent">true</item>
<item name="android:windowContentOverlay">#null</item>
<item name="android:colorBackground"> #android:color/transparent</item>
<item name="android:backgroundDimEnabled">true</item>
<item name="android:backgroundDimAmount">0.3</item>
<item name="android:windowFrame">#null</item>
<item name="android:windowIsFloating">true</item>
</style>

This is simplest solution for set transparent background of BottomSheetDialogFragment
It makes use of the following line of code:
((View) contentView.getParent()).setBackgroundColor(getResources().getColor(android.R.color.transparent));
Example in context:
public class ShareOneTouchAlertNewBottom extends BottomSheetDialogFragment {
#Override
public void setupDialog(Dialog dialog, int style) {
super.setupDialog(dialog, style);
View contentView = View.inflate(getContext(), R.layout.fragment_bottom_sheet, null);
dialog.setContentView(contentView);
CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) ((View) contentView.getParent())
.getLayoutParams();
CoordinatorLayout.Behavior behavior = params.getBehavior();
((View) contentView.getParent()).setBackgroundColor(Color.TRANSPARENT);
}
}

Sorry got it late here is what you are looking for upvote if u have done it successfully
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
((View) getView().getParent()).setBackgroundColor(Color.TRANSPARENT);
}
Add this line in bottom sheet dialog fragment's on activity created. This will do the trick

The following function override worked in a BottomSheetDialogFragment implementation:
class MyTopicBottomSheet : BottomSheetDialogFragment() {
override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
return super.onCreateDialog(savedInstanceState).apply {
// window?.setDimAmount(0.2f) // Set dim amount here
setOnShowListener {
val bottomSheet = findViewById<View>(com.google.android.material.R.id.design_bottom_sheet) as FrameLayout
bottomSheet.setBackgroundResource(android.R.color.transparent)
}
}
}
// Rest of your class here
}

Following the idea from Marco RS (that for me was the only solution at all that works), you can create a clean extension and apply wherever you want on your dialogs.
Extension:
fun BottomSheetDialogFragment.setTransparentBackground() {
dialog?.apply {
setOnShowListener {
val bottomSheet = findViewById<View?>(R.id.design_bottom_sheet)
bottomSheet?.setBackgroundResource(android.R.color.transparent)
}
}
Example:
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
setTransparentBackground()
}

Bit of a hack but it works for making background transparent. Obviously you can replace the 'transparent' with whatever colour you want.
mBottomSheetDialog.getWindow().findViewById(R.id.design_bottom_sheet).setBackgroundResource(android.R.color.transparent);

There are several hackish ways to do it. The way I solved this issue is the recommended way. Let's understand why?
In the docs, it's mentioned that
Modal bottom sheet. This is a version of DialogFragment that shows a bottom sheet using BottomSheetDialog instead of a floating dialog.
This means there should be a method that BottomSheetDialogFragment uses to replace the default Dialog with a BottomSheetDialog.
The only method BottomSheetDialogFragment overrides is onCreateDialog(). So we're gonna use this public method to override our dialog style.
Recommended Method
In the fragment that extends BottomSheetDialogFragment overrDide onCreateDialog() which is a public method exposed by BottomSheetDialogFragment itself.
override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
setStyle(STYLE_NO_FRAME, R.style.BottomSheetDialog)
return super.onCreateDialog(savedInstanceState)
}
besides that, in themes.xml override BottomSheetDialog theme and add transparent background.
<style name="BottomSheetDialog" parent="ThemeOverlay.MaterialComponents.BottomSheetDialog">
<item name="bottomSheetStyle">#style/BottomSheetModal</item>
</style>
<style name="BottomSheetModal" parent="Widget.Design.BottomSheet.Modal">
<item name="android:background">#android:color/transparent</item>
</style>
More about:
BottomSheetDialogFragment: here
onCreateDialog: here
theming the BottomSheetDialog: here

So, I figured out 2 solutions.
Best one:
Create an activity with transparent background just for your bottom sheet.
Implement your own layout with a coordinator layout and a bottom sheet.
Set the margin you want.
Set the content you want.
Not tested yet.
Lazy one:
Extends BottomSheetDialogFragment, in onActivityCreated add:
Resources resources = getResources();
// Set margin for Landscape Mode. Maybe a more elegant solution will be to implements our own bottom sheet with our own margins.
if (resources.getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) {
assert getView() != null;
View parent = (View) getView().getParent();
CoordinatorLayout.LayoutParams layoutParams = (CoordinatorLayout.LayoutParams) parent.getLayoutParams();
layoutParams.setMargins(
resources.getDimensionPixelSize(R.dimen.bottom_sheet_margin_left), // 64dp
0,
resources.getDimensionPixelSize(R.dimen.bottom_sheet_margin_right), // 64dp
0
);
parent.setLayoutParams(layoutParams);
}

I had same problem, nothing helped.
Used this code to solve the problem:
override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
val bottomSheet = (view!!.parent as View)
bottomSheet.backgroundTintMode = PorterDuff.Mode.CLEAR
bottomSheet.backgroundTintList = ColorStateList.valueOf(Color.TRANSPARENT)
bottomSheet.setBackgroundColor(Color.TRANSPARENT)
}
P.S. com.google.android.material:material:1.1.0-alpha09

BottomSheetDialog will get the R.attr.bottomSheetDialogTheme style from your context's theme, or else use the default R.style.Theme_Design_Light_BottomSheetDialog.
The layout xml of BottomSheetDialog is R.layout.design_bottom_sheet_dialog. The main content is a FrameLayout with id/design_bottom_sheet whose style is ?attr/bottomSheetStyle.
If you extends a style with parent Theme.Design.Light.BottomSheetDialog then all your default attrs like colorPrimary, colorAccent may be overrided. Thus ThemeOverlay is recommended to be used in View Theme tree. You should extend a style from ThemeOverlay.MaterialComponents.Light.BottomSheetDialog like this:
<style name="Widget.Test.ButtonSheetDialogTheme" parent="ThemeOverlay.MaterialComponents.Light.BottomSheetDialog">
<item name="bottomSheetStyle">#style/Widget.Test.BottomSheet.Modal</item>
</style>
<style name="Widget.Test.BottomSheet.Modal" parent="Widget.MaterialComponents.BottomSheet.Modal">
<item name="backgroundTint">#android:color/transparent</item>
</style>
You have to extend a style from Widget.MaterialComponents.BottomSheet.Modal, because the default style contains these:
<style name="Widget.MaterialComponents.BottomSheet" parent="Widget.Design.BottomSheet.Modal">
<item name="android:background">#null</item>
<item name="backgroundTint">?attr/colorSurface</item>
....
</style>
BottomSheetDialog's background is decided both by android:background and backgroundTint. But I am not sure why backgroundTint is effective while android:background is null. 🤔??
For more knowledge about Android Theme:
Android Styling: themes overlay

Late answer, but faced this problem myself and found better solution then any of suggested.
You can wrap your sheet layout with another layout with transparent background and add margin from it (16dp here):
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/transparent"
>
<android.support.v4.widget.NestedScrollView
android:layout_width="100dp"
android:layout_height="match_parent"
android:orientation="vertical"
android:layout_margin="16dp">
....
Then add transparent background to your sheet like in Gnzlt answer:
<style name="CustomBottomSheetDialogTheme" parent="Theme.Design.Light.BottomSheetDialog">
<item name="bottomSheetStyle">#style/CustomBottomSheetStyle</item>
</style>
<style name="CustomBottomSheetStyle" parent="Widget.Design.BottomSheet.Modal">
<item name="android:background">#android:color/transparent</item>
</style>
And voila, don't need another activity.

This worked for me.. Oncreate Dialog get the window set color
public Dialog onCreateDialog(Bundle savedInstanceState) {
Dialog dialog = super.onCreateDialog(savedInstanceState);
if(dialog.getWindow() !=null){
dialog.getWindow().setGravity(Gravity.BOTTOM);
dialog.getWindow().setBackgroundDrawableResource(android.R.color.transparent);
dialog.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND);
dialog.setCancelable(false);
}
return dialog;
}

use "setOnShowListener" for your dialog instance, like this in kotlin:
yourDialogInstance.setOnShowListener {
//this line transparent your dialog background
(dialogView.parent as ViewGroup).background =
ColorDrawable(Color.TRANSPARENT)
}
complete code in kotlin :
BottomSheetDialog(this).apply {
val dialogView = LayoutInflater.from(context)
.inflate(R.layout.your_dialog_layout, null, false)
setContentView(dialogView)
setOnShowListener {
(dialogView.parent as ViewGroup).background =
ColorDrawable(Color.TRANSPARENT)
}
show()
}

This is your answer :D
View contentView=LayoutInflater.from(getContext()).inflate(R.layout.bs_add_event,null);
mBottomSheetDialog.setContentView(contentView);
CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) ((View) contentView.getParent()).getLayoutParams();
params.setMargins(50,50,50,50); // set margin as your wish.
and also change android:layout_width="100dp" in nestedScroolView to
android:layout_width="match_parent"

1. Firstly Add Style in your theme:
<style name="MyTransparentBottomSheetDialogTheme" parent="Theme.AppCompat.Light">
<item name="android:background">#android:color/transparent</item>
<item name="android:colorBackground">#android:color/transparent</item>
</style>
2. Then attach above style with BottomSheetDialogFragment same as below :
#Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
return new BottomSheetDialog(getContext(),R.style.MyTransparentBottomSheetDialogTheme);
}

1 - Initialize the bottom sheet dialog this way.
BottomSheetDialog bottomSheetDialog = new BottomSheetDialog(YourActivity.this, R.style.BottomSheetDialog);
2 - Add this style as suggested by Gnzlt.
<style name="BottomSheetDialog" parent="Theme.MaterialComponents.Light.BottomSheetDialog">
<item name="bottomSheetStyle">#style/BottomSheetDialogStyle</item>
</style>
<style name="BottomSheetDialogStyle" parent="Widget.MaterialComponents.BottomSheet.Modal">
<item name="android:background">#android:color/transparent</item>
<item name="android:backgroundTint">#android:color/transparent</item>
</style>

I know this question is old but I still answer the question and hope it useful.
By default, the layout specified in onCreateView() method will be added to a FrameLayout with white background by BottomSheetDialogFragment. Therefor, you should set the FrameLayout's background to transparent in onStart() method.
class YourDialog() : BaseBottomDialog() {
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
return inflater.inflate(R.layout.layout_your_dialog, container, false)
}
override fun onStart() {
super.onStart()
(view!!.parent as View).setBackgroundColor(Color.TRANSPARENT)
}
}

Found that I needed to use a variant on the accepted answer, by updating to MaterialComponents to make compatible with AndroidX as well as adding "backgroundTint" as transparent as well:
<style name="BottomSheetDialog" parent="Theme.MaterialComponents.Light.BottomSheetDialog">
<item name="bottomSheetStyle">#style/BottomSheetDialogStyle</item>
</style>
<style name="BottomSheetDialogStyle" parent="Widget.MaterialComponents.BottomSheet.Modal">
<item name="android:background">#android:color/transparent</item>
<item name="android:backgroundTint">#android:color/transparent</item>
</style>
Apply the "BottomSheetDialog" style to the fragment as per the original answer:
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setStyle(BottomSheetDialogFragment.STYLE_NORMAL, R.style.BottomSheetDialog);
}

Just Add the following code in your style.xml
<style name="BottomDialogStyle" parent="Theme.Design.Light.BottomSheetDialog">
<item name="android:windowIsFloating">false</item>
<item name="android:statusBarColor">#android:color/transparent</item>
<item name="android:windowSoftInputMode">adjustResize</item>
<item name="bottomSheetStyle">#style/CustomBottomSheetStyle</item>
</style>
<style name="CustomBottomSheetStyle" parent="Widget.Design.BottomSheet.Modal">
<item name="android:background">#android:color/transparent</item>
</style>
Also, update the onCreate
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setStyle(STYLE_NORMAL, R.style.BottomDialogStyle)
}

If you are using BottomSheetBehavior then use the below code on collapse and Expand states
behavior.setState(BottomSheetBehavior.STATE_EXPANDED); ((View)getParent()).setBackgroundColor(getResources().getColor(<your desire color>));
and
behavior.setState(BottomSheetBehavior.STATE_COLLAPSED); ((View).getParent()).setBackgroundColor(getResources().getColor(android.R.color.transparent));
Also, use
behavior.setBottomSheetCallback(new BottomSheetBehavior.BottomSheetCallback() {
#Override
public void onStateChanged(#NonNull View bottomSheet, int newState) {
if (newState == BottomSheetBehavior.STATE_COLLAPSED) {
((View) mScrollview.getParent()).setBackgroundColor(getResources().getColor(android.R.color.transparent));
}
}
#Override
public void onSlide(#NonNull View bottomSheet, float slideOffset) {
// React to dragging events
}
});

If you want all your BottomSheets inherit that behavior, just do as follows:
<style name="Theme.InstaDownloader" parent="Theme.MaterialComponents.Light.NoActionBar">
...
<item name="bottomSheetDialogTheme">#style/BottomSheetTheme</item>
...
</style>
<style name="BottomSheetTheme" parent="Theme.Design.Light.BottomSheetDialog">
<item name="bottomSheetStyle">#style/BottomSheetStyle</item>
</style>
<style name="BottomSheetStyle" parent="Widget.Design.BottomSheet.Modal">
<item name="android:background">#android:color/transparent</item>
</style>

For me below worked:
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
(view.parent as? View)?.setBackgroundColor(Color.TRANSPARENT)
}

<style name="BaseBottomSheetDialogTrasn" parent="#style/Theme.Design.Light.BottomSheetDialog">
<item name="android:windowIsFloating">false</item>
<item name="bottomSheetStyle">#style/BottomSheetTrans</item>
</style>
<style name="BottomSheetDialogThemeTrans" parent="BaseBottomSheetDialogTrasn">
<item name="android:statusBarColor">#android:color/transparent</item>
<item name="android:navigationBarColor">#color/white</item>
</style>
<style name="BottomSheetTrans" parent="#style/Widget.Design.BottomSheet.Modal">
<item name="android:background">#android:color/transparent</item>
</style>
And finally add the parameter in BottomSheetDialog(context,R.style.BottomSheetDialogThemeTrans)

I know I'm much late but in kotlin the thing that really helped me out is adding this line in your fragment in onCreate():
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setStyle(STYLE_NORMAL,R.style.CustomBottomSheetDialog)
}
And in styles():
<style name="CustomBottomSheetDialog" parent="Theme.Design.Light.BottomSheetDialog">
<item name="bottomSheetStyle">#style/bottomSheetStyleWrapper
</item>
</style>
<style name="bottomSheetStyleWrapper"
parent="Widget.Design.BottomSheet.Modal">
<item
name="android:background">#android:color/transparent</item>
</style>
Works perfectly fine for me.

Adding android:background or android:colorBackground property will not make the bottom sheet transparent as suggested by many answers!
Adding, backgroundTint to sheetStyle is the key to making bottomsheet transparent.
Eg:
<style name="BottomSheetDialog" parent="Theme.Design.Light.BottomSheetDialog">
<item name="bottomSheetStyle">#style/BottomSheetStyle</item>
</style>
The following piece is key,
<style name="BottomSheetStyle" parent="Widget.MaterialComponents.BottomSheet.Modal">
<item name="backgroundTint">#android:color/transparent</item>
</style>
Pass this style as second parameter while creating the BottomSheetDialog in java or kt.
Eg:
BottomSheetDialog(context, R.style.BottomSheetDialog)
Resource:
A good resource to learn more about BottomSheet https://m2.material.io/develop/android/components/bottom-sheet-dialog-fragment

Fullscreen DialogFragment with translucent StatusBar

I have a DialogFragment which I want to show in fullscreen. I do however still want a StatusBar present, and the hardware buttons at the bottom. I also want to set a background color of the StatusBar (for Lollipop).
My problem is that if I set the following flags in the DialogFragment:
getWindow().addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
Both the StatusBar and Hardware keyboard becomes translucent, and the DialogFragment stretches behind these.
Here is the code, which has been greatly reduced to become readable:
public class CardDetailsDialog extends DialogFragment {
Setup parameters...
public static CardDetailsDialog newInstance(final long cardId, final long projectId){
CardDetailsDialog frag = new CardDetailsDialog();
frag.setStyle(DialogFragment.STYLE_NORMAL, R.style.CardDetailsDialogStyle);
return frag;
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
if(getDialog() != null) {
getDialog().getWindow().addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
getDialog().getWindow().clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
getDialog().getWindow().getAttributes().windowAnimations = R.style.DialogSlideAnimation;
getDialog().getWindow().setLayout(LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.MATCH_PARENT);
getDialog().getWindow().setStatusBarColor(Color.RED);
}
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
View view = inflater.inflate(R.layout.card_details, container, false);
Handle everything that happens inside the view...
return view;
}
}
Here is the referred theme:
<style name="CardDetailsDialogStyle" parent="#style/Theme.AppCompat.Light.Dialog" >
<item name="android:windowBackground">#null</item>
<item name="android:windowNoTitle">true</item>
<item name="android:windowFrame">#null</item>
<item name="android:windowIsFloating">true</item>
<item name="android:windowContentOverlay">#null</item>
<item name="android:windowAnimationStyle">#android:style/Animation.Dialog</item>
<item name="android:windowSoftInputMode">stateUnspecified|adjustPan</item>
</style>
And the style of the fragment:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/pp.whiteBackgroundColor" >
<android.support.v7.widget.Toolbar xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/card_details_toolbar"
android:layout_height="wrap_content"
android:layout_width="match_parent"
android:layout_alignParentTop="true"
app:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:popupTheme="#style/PopupMenutheme">
</android.support.v7.widget.Toolbar>
<ScrollView
android:id="#+id/details_scrollview"
android:layout_height="wrap_content"
android:layout_width="match_parent">
All subview elements here...
</ScrollView>
</RelativeLayout>
This is the result:
As you can see, the ToolBar extends over the StatusBar and hardware buttons. I don't know if I am approaching this correctly. Am I missing something?
EDIT
This is what the same view look likes when I remove
getDialog().getWindow().addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);

For anyone who's still having this problem, do the following. This just solves half of the problem that is posted i.e. black status bar.
Add following theme to res/value-v21/style
<style name="DialogTheme" parent="#style/Base.Theme.AppCompat.Light.Dialog">
<item name="android:windowTranslucentStatus">true</item>
</style>
And then apply Style on DialogFragment in onCreate
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setStyle(DialogFragment.STYLE_NO_TITLE, R.style.DialogTheme);
}
Edit
if you've problem with your dialog theme then use this style e.g. colorAccent or colorControlHighlight etc
<style name="DialogTheme" parent="#style/ThemeOverlay.AppCompat.Dialog">
<item name="android:windowTranslucentStatus">true</item>
</style>

In my case SYSTEM_UI_FLAG_LAYOUT_STABLE solved problem with overlapping
int width = ViewGroup.LayoutParams.MATCH_PARENT;
int height = ViewGroup.LayoutParams.MATCH_PARENT;
dialog.getWindow().setLayout(width,height);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
dialog.getWindow().addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
dialog.getWindow().setStatusBarColor(getResources().getColor(R.color.darkGrayTransp));
dialog.getWindow().getDecorView().setSystemUiVisibility(SYSTEM_UI_FLAG_LAYOUT_STABLE);//solves issue with statusbar
dialog.getWindow().setGravity(Gravity.CENTER_HORIZONTAL| Gravity.TOP);
}

Try use the same Style from your App. I tested with simple dialog without fragment and works fine.
Like that:
new Dialog(context, R.style.CardDetailsDialogStyle);

You have to set fitsystemwindows = true. Other way is to add a Space with 0dp and change its height to 25dp when the dialog is going to show.
To change the space size, use layout params, check this post: How to create a RelativeLayout programmatically with two buttons one on top of the other?

<style name="DialogTheme" parent="Theme.AppCompat.Light.NoActionBar">
<item name="android:windowTranslucentStatus">true</item>
<item name="android:windowNoTitle">true</item>
<item name="android:windowFullscreen">true</item>
<item name="android:windowIsFloating">false</item>
</style>

Just apply android:fitsSystemWindows="true" to your root ViewGroup:
`<FrameLayout
android:fitsSystemWindows="true">
<View .../>